Optessa RTS: Real Time Sequencing & Scheduling

RTS is Optessa’s on demand Real Time Scheduling software

Optessa Real Time Scheduling (RTS) is a unique solution for the real-time event-driven scheduling needs of modern automated manufacturing plants in diverse industries such as automotive, semiconductor, batch processing etc. and also in warehousing / logistics operations to enable optimized real-time order fulfillment. Optessa RTS combines powerful optimization, based on the Optessa sequencing and scheduling engine, with a real-time architecture.

The system is typically integrated with plant level MES / tracking / control systems and combines predictive optimization with tracking of upstream events.

Optessa RTS is capable of generating optimal scheduling/sequencing and routing decisions. Optessa RTS solutions have been demonstrated to be significantly superior to custom logic developed in MES systems or programmed into controllers like PLCs.

A typical application for Optessa RTS in the auto industry is the sequencing out of painted vehicle bodies from a WIP buffer, such as an Automated Storage and Retrieval System (ASRS) or a lane bank. Optessa RTS generates optimal real-time sequences based on the buffer WIP and upstream tracking. These sequences are used to provide “what next” decisions for the vehicles for Final Assembly (Trim).

A similar application from the semiconductor industry would be a process stage requiring real-time scheduling and routing decisions. For example, at the photolithography operation FOUPs (enclosures holding silicon wafers) waiting processing in the buffer need to be routed to the appropriate tool, while considering constraints such as reticle availability. This involves routing decisions, “where next” for FOUP,
and scheduling decisions, “what next” for tool. Optessa RTS has the speed and flexibility to make these rapid decisions while integrated with the MES / RTD systems.

The strengths of Optessa RTS derive from its superior technology and its unique real time architecture which addresses real time event driven scheduling needs in diverse manufacturing industries. Here are some of the key strengths of Optessa RTS:

Powerful Optimization Engine

The powerful optimization engine combined with the real-time architecture of Optessa RTS enable the system to generate optimal decisions within the time window constraints of an automated plant, which may require multiple decisions every minute in order to maintain throughput.


Enable as late as possible rescheduling decision to ensure that all necessary events are considered when making the scheduling or routing decision.


The system maintains a tracking image of upstream (previous operations) and related (inventory) events, which enables synchronizing of upstream and downstream schedules to maintain high throughput.


Optessa RTS maintains a reference to a “corporate” / “orders” schedule (base schedule) when making the in-plant real-time scheduling decisions. Since MRP and procurement is driven by the base schedule, the system maintain a bias to the base schedule to ensure that in-plant scheduling decisions do not unnecessarily deviate from the base schedule and, hence, ensures material stability.

Late order allocation / substitution

When making a “jobs” schedule, Optessa RTS can also reference and allocate jobs to orders. For example,
in an auto plant the system can generate real-time Final Assembly sequences and allocate sales orders to painted vehicle bodies in a single optimization process. This enables late assignment of the sales order to a “job” (painted car body identified by Model Style and Color) which significantly improves flexibility and enables VIN stamping at the Final Assembly stage.